Question

In a counter flow heat exchanger, cold fluid enters at 30\(^\circ\)C and leaves at 50\(^\circ\)C, whereas the hot fluid enters at 150\(^\circ\)C and leaves at 130\(^\circ\)C. What is the mean temperature difference?

• A. 50\(^\circ\)C
• B. 120\(^\circ\)C
• C. 80\(^\circ\)C
• D. 100\(^\circ\)C

Hint:

For any counter-flow heat exchanger, if the temperature drop of the hot fluid equals the temperature rise of the cold fluid, the temperature differences at both ends are identical (\(\Delta T_1 = \Delta T_2\)). In this case, you do not need to use logarithms; the LMTD is simply equal to this common temperature difference.

Answer 1

The Correct Option is D